As the Eagles began their final days of spring practices Tuesday, coach Andy Reid said the energy his team has shown has stemmed from their biggest name, quarterback Michael Vick.

"Michael knows what he needs to do and he's worked like crazy. One of the reasons that we've had the attendance here that we've had and one of the reasons that we've had energy is Michael Vick," Reid said.

The quarterback, facing a critical year for himself and the team, hasn't missed a workout, Reid said.

"He's the one who's out here motivating that energy and making the players around him be here," Reid said.

Over the last three weeks of voluntary, full-team practices, Reid has spoken often about the positive energy the Eagles have carried from a four-game winning streak that added late gloss to a disappointing 8-8 season.

"We just feel like we should have accomplished a lot last year," Vick said.

Three days of mandatory practices for veterans and rookies began Tuesday. They will be the last formal team activity until training camp opens July 22.

Cornerback Nnamdi Asomugha said these offseason practices are a far better way to begin than the hurried start that greeted players after last year's NFL lockout.

"It's very calm, it's different from how it was when we started off last year. I think we know each other ... that's big for a team like ours and we're building," Asomugha said. "We did a lot of the right things last offseason, so now we're just putting it together with more time."

Vandervelde snaps

One roster question facing the team is who will back up center Jason Kelce now that veteran Jamaal Jackson has been released.

One option is second-year lineman Julian Vandervelde, who took some reps at center Tuesday. Vandervelde was drafted in the fifth round in 2011 but played in just one game. He fits the mold preferred by offensive line coach Howard Mudd and might get a shot as a reserve.

Cox excused

Defensive tackle Fletcher Cox was the only member of the 87-man roster who missed practice Tuesday. He was excused after a cousin died in a car accident.

Asomugha, wide receiver DeSean Jackson, running back LeSean McCoy, and cornerback Dominique Rodgers-Cromartie were all back at practice Tuesday. Each missed some or all of last week's voluntary practices because of personal reasons.

Defensive end Vinny Curry (ankle) was not at practice but was at the team's facility.

Tryouts added

The Eagles brought three players to the minicamp as tryouts: linebacker Ryan Rau, defensive end Frank Trotter (no relation to former linebacker Jeremiah Trotter), and wide receiver Raymond Webber. They do not count against the 90-man roster limit.